Rubber sole.



F. BOYLE.

RUBBER SOLE.

APPLICATION FILED DEC.24| 1914.

1,137,724. Patnted Apr. 27, 1915.

WW6; Qvwewtom wiimmm ,WI ED STATES PATENT OFFICE.

raancisnorm, or NEWIORK, N. Y., ASSIGNOB 'ro UNITED snares RUBBERcompany, .A CORPORATION or NEW messy.

' I f; R BBER so n.

specification of Letters Eaten; Patented Apr, 2' 7, 1915.-

Application flJed'Decembr 24,1914. am-151m. 878.908. e

To all whom it may concern .i;

Be it known that I, FRANCIS BOYLE, a citizen of the United-States, and aresident of New York, county of New York, State of New York, haveinvented;?certain new and useful Improvements in the Manufacture ofRubber Soles, of which the following is a full, clear, and exactdescriptlon.

My invention relates to soles 1 for boots and shoes, and moreparticularly to rubber soles.

In the manufacture of shoes provided with rubber soles it has beencustomary --to attach the rubber sole directly to the leather sole orWelt of the shoe by fastenings, such as stitches, metallic nails, etc.This construction has proved very unsatisfactory because the rubber solequickly snubs off 1n chunks at the edge back to the line of thefasteners due to forcible impact with hard obstacles, thereby looseningthe fastenings, breaking away from the leather sole or welt, and quicklybecoming unfit for use.

It is the object of my invention to provide a rubber ,sole which can bestitched, nailed, or otherwise secured to the leather sole or welt, andwill be capable of superior wearing qualities and superior retainingqualities for the fastening devices, and which shall be also neat andattractive in appearance, and retain its edge line intact much longerthan has hitherto been possible in rubber soled boots and shoes.

To attain these results I provide a rubber sole embodying a tread and abacking therefor, especially adapted to withstand the wear and usage towhich they are individu ally subjected, while at the same time form inga unitary structure.

By my invention I provide a rubber sole in which the tread portionthroughout is stiffer and stronger than the backing, whereby it is lessliable to break or chip from impact with hard substances, and form afirm anchorage for the fastening means, such as stitches, nails, etc,and is more durable than ordinarily, thus, through the prolonging of thelife and appearance of the tread, prolonging the life of the entiresole.

The invention consists in a sole for a boot or shoe embodying therein anintegral mass of vulcanized rubber, comprising a tread of relatively-firm, tough, strong and comparatively unyielding rubber and a backingtherefor of more or less yielding and elastic rubber, and in such othernovel features as are hereinafter set forth and described and more,particularly pointed out in the appended claims.

.- In the accompanying drawing: Figure 1 .is a side elevation of a shoeequipped with a rubber [sole embodying my invention; Eig. 2 isafragmentary bottom view of the shoe shown in Fig. 1.

Referring to the drawing 10 designates a shoe having secured to theleather welt sole 1 1' a sole embodying a tread 12 of relatively firm,tough, strong and comparatively unyielding rubber, and a backing 13integral therewith, of more or less soft and elasticusual cushionfunction so desirable in rubber soles.

The tread is preferably of such consistency as to approximate leather instiffness whereby stitch-retaining and marginal edgeretaining qualitiesapproximating that of leather will be produced in the sole, while at thesame time the product,will be charac terized by an absence of theseparable strata existent in the combination of a leather tread witharubber backing.

In one embodiment of my invention I make the tread and backing of thesame grade of rubber stock but incorporate more sulfur or othervulcanizing agent in the tread than in the backing, so that duringvulcanization the tread will partake of a firmer, tou her, and lessyielding body than the bac ing. I also accomplish the same result bymaking the tread and backing of the same or even different rubbercompounds and initially partially curing the tread so that duringvulcanization in contact with thebacking the additional heat will effectthe desired degree of firmness and strength in the tread. I also effectthe same result by making the tread and backing respectively ofdifierent grades of rubbefstock which inherently have the relativephysical 'characteristics desired in the product.

either before or after cutting from the Oil sheet; and finally to curethe cut soles a vulcanizer. The tread and backlng 1111- tially adhereintimately with each other at their contacting surfaces and subsequentlyflow together during vulcanization and.

form a unitary integral mass, in difl'erent portions of which existdifi'erent qualities adapted to withstand'thewear and usage resides inthe embodiment in a rubber sole stand of inseparable strata or layershaving different 'u'a lities which adapt them to witht e wear and usageto which they are individually subjected.

' What is claimed is:

' A vulcanized rubber sole of unitary in-f tegral structure embodying 'abottom layer of sti-fi, tough and comparatively non-compressibleconsistency, adapted to form a firm anchorage for securing means, and anupper layer of yielding elasti&consistency adapted to form a cushion.

Signed at of New York, this 23rd day of December,'

FRANCIS BOYLE. 1

'Witnesse's:

SAMUEL C. YEATON, DANIEL A..W1Lcox.

New York, county and State

